<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>添加和去除节点的内联style</title>
</head>

<body>
  <div id="ad_position_box">简简单单的生活</div>
  <div id="feedback" style="background-color: tomato;">我吃了早餐</div>

  <script>
    var domdiv = document.getElementById("ad_position_box");
    domdiv.style.backgroundColor = "#ffeb3b"; //添加style属性，设置背景颜色

    var feedback = document.getElementById("feedback");
    feedback.style.cssText = "";//清空style样式
  </script>
</body>

</html>